2-(4-Methoxybenzyl)phenyl 6-O-ethoxycarbonyl-β-D-glucopyranoside represented by formula (I):
is a novel compound not known in literatures, which has been found by the present applicant. This compound is converted to an active form of 2-(4-methoxybenzyl)phenyl β-D-gluco-pyranoside in vivo, which exhibits excellent inhibitory activities against SGLT2 and is useful for the treatment or prevention of diseases associated with hyperglycemia such as diabetes mellitus, diabetic complication, obesity and the like. None of crystalline form of this compound has been known so far.